dim headlight on '79 p200

Need help? Want to help? Discuss technical issues and share tips.
epsato
Posts: 2223
Joined: Wed Jul 12, 2006 1:19 pm
Location: Logan's Circle
Contact:

dim headlight on '79 p200

Postby epsato » Thu Sep 06, 2012 11:15 am

I've got a p200 with a dim headlight. I replaced the battery, replaced the bulb and checked the connections. everything seems fine.

I noted that with the key switch on, all lights go on, except the headlight. The light does seem to rev with the engine, but it's hella weak.

Any ideas? Reading around the 'web I'd thought the regulator might need replacing, though I've heard they're a bear to find for old p200s. The other thing I've heard is that perhaps the flywheel needs to be remagnetized.

Before dropping cash on a regulator or finding a place to deal with the flywheel, anyone got recommendations on what may need a fixin?

User avatar
porter
Posts: 349
Joined: Wed Mar 12, 2008 4:12 pm
Location: lutherville, md

Re: dim headlight on '79 p200

Postby porter » Thu Sep 06, 2012 11:26 am

It sounds like the headlight only works with the motor running, is that what you are saying?
So, the chrage that it is getting is straight from the stator, without the battery involved. I am not sure if this is suposed to be this way or not, it depends on your model and diagram.

I have a few ducati 3 and 5 pole regulators if you need. Yes, remagnetizing can be done, but usually, this is when the flywheel is way old. You could try to hook a large screwdrive to it, I have heard that if it sticks, then the flywheel is good enuf.

Elaborate more so I can help.

epsato
Posts: 2223
Joined: Wed Jul 12, 2006 1:19 pm
Location: Logan's Circle
Contact:

Re: dim headlight on '79 p200

Postby epsato » Thu Sep 06, 2012 11:39 am

Porter, you are correct.

The headlamps on only when the engine is. The P has a battery, but when i looked at the wiring on the engine, it doesn't match up with typical P series electrical diagrams.

Battery P, but the headlamp only seems to run when the engine's on.

I do believe the light's straight off the stator.

User avatar
porter
Posts: 349
Joined: Wed Mar 12, 2008 4:12 pm
Location: lutherville, md

Re: dim headlight on '79 p200

Postby porter » Thu Sep 06, 2012 12:06 pm

I think that there are 2 different stator setups for P's. A double yellow lead off of the stator, and a single yellow lead version.
The single lead version is battery-less, and AC, it simply powers the lights off of the stator, end of story, usually, these P's have no blinkers, as AC blinkers are difficult.

The double is DC, it does use and charge a battery, and also runs some of the power right off of the stator, so its balanced, and it uses the battery when it needs it.

If you have a battery, my guess is that you should have the charging system, or a double yellow feed from the stator, along with the cdi wires.
What I would do to trouble shoot things is to get a multimeter and work backwards from the headlight to the switches, to find faults along the way to the battery, if that's where the origin of the headlight beam circuit is.

And, point us to the wiring diagram on scooterhelp that matches your setup. From there its alot easier to diagnose.

User avatar
Mikeh
Posts: 873
Joined: Wed Oct 04, 2006 2:36 pm

Re: dim headlight on '79 p200

Postby Mikeh » Thu Sep 06, 2012 3:25 pm

Yup there are two different US model P200 wire diagrams and Stator plates.The floating ground, and the non-floating ground type.

The regulators/rectifiers are usually shot in the older P200's.

The wires on the stator are also usually shot on the older P200's.

The Harnesses are usually OK with minor conncector repaires required and the entire green kill wire usually needs to be replaced.

Sounds like you will need an overhaul on this stuff. You gotta pull the stator, solder new wires onto it, make sure it's wired for for maximum AC to headlight (two coils to headlight) and then two coils for DC production, then check the harness for shorts and bad wires (this is usually at the terminals), and also replace the regulator with an aftermarket one.

You can play with the Two coils for AC headlight power by running them in series or parrallel, i can't remember which is better (i think series). For DC power production you will want to run from two coils but depending upon the regulator/rectifier you use you may want a floating ground (one coil feeds to the other), or you may want to ground the end of each coil and feed the wires into the regulator/rectifier.

I go with grounded coils for DC, one of each with a simple MSR type generic ACregulator on each output wire (these regulate voltage to 14 volts), then feed these two wires into a rectifier (I get rectifiers from my local Bainesville electronic's store, they costs about $8). I then get a solid 14 volts DC to feed into the battery. I locate the DC stuff where the old regulator used to be.

The best place to regulate the headlight AC power is just behind the headlight in the headset. I splice into the wire that goes to the hi/low beam switch with a MSR type regulator there. Just make sure that you have a good ground wire to connect the other side of the regulator to. If your regulator is not grounded then you will get a voltage spike and may blow bulbs.

Last night Porter was telling me about an alternate to the Bainesville rectifier and MSR regulators. I beleive it was a podtronics unit but i don't know what model or where he bought it from - i think he used it on his Lammy.

Good luck,

It's a headache if you have not done it before.

epsato
Posts: 2223
Joined: Wed Jul 12, 2006 1:19 pm
Location: Logan's Circle
Contact:

Re: dim headlight on '79 p200

Postby epsato » Thu Sep 06, 2012 5:31 pm

Found out from the prior owner that the scoot's got the trailtech rectifier/regulator.

Prior owner suggested it might be the stator and that the flywheel's not a likely culprit thanks to strong spark...

User avatar
Mikeh
Posts: 873
Joined: Wed Oct 04, 2006 2:36 pm

Re: dim headlight on '79 p200

Postby Mikeh » Thu Sep 06, 2012 5:51 pm

Sounds like it's already been half messed with. I hear that Trail Tech makes good stuff. But you may need to find out what type of input from the stator will make the trail tech unit work the best (floating ground or not) and then rewire the stator so that you get optimal output. i think it may need a floating ground.

and yes, the flywheel is usually not the problem. If the motor fires up and runs with good spark then the flywheel is likely ok and the other coils are just not wired to work well with the trail tech unit.

User avatar
12CI
Posts: 1255
Joined: Fri Jul 07, 2006 8:47 pm
Location: Greenbelt

Re: dim headlight on '79 p200

Postby 12CI » Fri Sep 07, 2012 12:08 am

check the simple things first. clean the lamp socket and all of the connectors, and check that the wires aren't corroded, frayed, cracked and-or loose at them. use that multimeter to check for high resistance / voltage drop at each one, too. don't forget to check the ground wire.

be sure to give them a shpritz of dielectric grease when re-assembling, to ward off future corrosion.

check that the lamp is the correct one, too. is it still a sealed beam, or has someone converted it to an H4?
as shameless as I am tactless and guileless

User avatar
dcunited4life
Posts: 114
Joined: Mon May 14, 2012 3:38 pm
Location: Denver City Denver

Re: dim headlight on '79 p200

Postby dcunited4life » Wed Sep 12, 2012 8:56 am

My 1979 P200e has the same issue only worse, no headlight at this point. Other issues mentioned here have been tracked down and slowly fixed and I am getting to the point where I too believe I have an issue with one or both of the coils on the stator that power the headlight.

My stator is the US double Yellow battery version. My Voltage regulator was bad as well so I got one for $8 off ebay. All of the wiring on my stator has been replaced with new stuff to combat the dreaded green wire rot. This leads me to believe we are dealing with a situation where there is an issue with one or both of the coils which drive the power to the headlight are bad. Next on my list is to check the power coming off the stator for the headlight. I have read that the purple wire is the headlight wire. I am going to be checking that with a multimeter.

I can for the life of me figure out how a wrap of copper wire goes bad but I guess that's what happens, and often on these older P's. It may just be a matter of time for you as well. Thankfully it's looking like a replacement coil or two are about $30 each Rather than around $175 for a new stator plate.

User avatar
12CI
Posts: 1255
Joined: Fri Jul 07, 2006 8:47 pm
Location: Greenbelt

Re: dim headlight on '79 p200

Postby 12CI » Wed Sep 26, 2012 9:14 pm

sorry if i'm being redundant (or pedantic) but...

are you sure the problem is in your stator, and not in the loom (wiring harness) somewhere else?

you could have something as simple as a bad hi/lo switch. if you have not already explored that, its certainly worth looking at.
as shameless as I am tactless and guileless


Return to “Service Center”

Who is online

Users browsing this forum: No registered users and 6 guests